Russula baniyakundensis A. Ghosh, K. Das & D. Chakr., 2021

Ghosh, Aniket, Das, Kanad & Chakraborty, Dyutiparna, 2021, Morphology and molecular approach reveal a new species of the genus Russula subsect. Lepidinae (Russulaceae) from India, Phytotaxa 483 (3), pp. 244-254 : 249-250

Russula baniyakundensis A. Ghosh, K. Das & D. Chakr. , sp. nov. Figs. 2 & 3

MycoBank: MB 836517

GenBank: MT 845821 (ITS Holotype) and MT 845820 (ITS Paratype)

Etymology:—Refers to “Baniyakund” in Uttarakhand ( India), the type locality.

Diagnosis:—Pileus medium to large-sized, reddish white, pale orange or light orange, pale red, pastel red to reddish orange, red colour of pileus descending to lamellae edge, context (both pileus and stipe) hard; taste bitter; basidiospores with relatively high (up to 1.2 µm) cylindrical to conical spines; hymenial cystidia distinctly thickwalled, cylindrical to fusiform with obtuse-rounded or appendiculate apex with heteromorphous contents without reaction in SV; pileipellis thick, hyphal terminations in suprapellis composed of chains of 1–2 branched cells; terminal cells apically obtuse-rounded; pileocystidia 1-celled, thick-walled, apically obtuse-rounded, with heteromorphous contents that never react with SV.

Holotype:— INDIA. Uttarakhand: Rudraprayag district, Baniyakund , N 30°29.016’ E 79°10.650’, elevation 2636 m, 23 rd July 2016, A. Ghosh, AG 16-1162 ( CAL 1806 , holotype!).

Description:— Basidiomata 59–128mm in height. Pileus medium to large-sized, 38–112mm in diam.,hemispherical when young, becoming convex, plano-convex to applanate with broadly depressed centre; margin decurved to plane in maturity, entire, obscurely tuberculate-striate near margin; surface viscid and shiny when wet, dull with drying, peeling to 1/4 th of the radius, orange-white or reddish white (6–7A2), pale orange or light orange (6A3–4) or pale red, pastel red or peach (7A3–5) to reddish orange (7A6–7). Pileus context up to 7 mm thick at the disc, compact, brittle, firm, chalky white (1–2A1), unchanging after bruising or on exposure. Lamellae adnexed to subdecurrent, subdistant to close (7–11/cm broad at pileus margin), chalky white (1–2A1) when young becoming yellowish white (1–2A2) with age, up to 7 mm broad at disc, forked near the stipe apex and middle, unchanging after bruising or on exposure, edges marginated with red (10A7) only near the pileus margin, entire; lamellulae absent. Stipe 50–95 × 14–18 mm, robust, firm, brittle, cylindrical, sometimes tapered at base, centrally attached; surface dry, finely longitudinally venose, chalky white (1–2A1) often with pastel red or pink rose or pastel pink to red (10–11A4–6) flush. Stipe context chalky white (1–2A1), solid, firm, unchanging after bruising or on exposure; turning salmon pink (6A4) with the application of FeSO 4 and negative (–ve) in guaiacol. Odour not distinctive. Taste somewhat bitter. Spore print palest cream (IIa).

Basidiospores (5.5–)6.7– 7.1 –7.5(–8) × (5.5–)5.9– 6.3 –6.8(–7.2) μm, Q=(1.0–)1.05– 1.12 –1.19(–1.33), globose, subglobose to broadly ellipsoid; ornamentation amyloid (projecting up to 1.2 µm), composed of cylindrical to conical spines, mostly connected with line connections, some isolated, some fused, forming an incomplete reticulum; suprahilar plage amyloid; apiculi up to 2 μm long. Basidia (39–)38.9– 44.5 –50.1(–56) × (10–)10.4– 11.2 –11.9(–12) µm, 4-spored, clavate; sterigmata up to 8 µm long. Hymenial cystidia near the lamellae faces (60–)70– 86.5 –102(–123) × (6–)8.6– 10.2 –11.8(–13) µm, abundant, cylindrical to fusiform with obtuse-rounded or appendiculate apex, with distinctly thickened walls, emergent up to 55 μm above the other elements of the hymenium, some deeply embedded; content dense, heteromorphous, thickly crystalline, without reaction in SV. Lamellae edges fertile with basidia and cystidia. Hymenial cystidia near the lamellae edges usually smaller and narrower, measuring (53–)56.7– 66.3 –75.9(–80) × (8–)7.8– 8.6 –9.4(–10) µm, cylindrical to fusiform with obtuse-rounded apex, with distinctly thickened walls; content dense, heteromorphous, thickly crystalline, without reaction in sulfovanillin (SV). Subhymenium layer up to 25 µm thick, pseudoparenchymatous. Hymenophoral trama mainly composed of large nests of sphaerocysts and intermixed with some hyphal elements. Pileipellis orthochromatic in Cresyl Blue, sharply delimited from the underlying sphaerocysts of the context, 120–160 μm thick, two-layered, distinctly divided into a 80–100 μm deep suprapellis composed of erect or ascending hyphal terminations, arranged in a trichodermal structure and dispersed pileocystidia, and a subpellis 40–60 μm deep, composed of more or less dense, horizontally oriented, tightly compact hyphae. Acid-resistant incrustations absent. Hyphal terminations near the pileus margin very flexuous, thin-walled, composed of chains of 1–2 cells, usually branched at the subterminal cells or the cells just below; terminal cells (16.5–)25.7– 39.7 –53.8(–68.8) × (3.5–)3.7– 4.3 – 5(–6) μm, mainly cylindrical or slightly narrowed towards base, often occasionally nodulose, apically obtuse-rounded; subterminal cells usually equally wide and usually branched, occasionally with lateral projections or nodulose. Hyphal terminations near the pileus centre flexuous, thin-walled; terminal cells slightly shorter and less wide, measuring (24–)28.3– 38.1 –47.8(–56) × (2.9–)3.4– 3.8 –4.1(–4.7) μm, mainly cylindrical to subcylindrical, apically obtuse-rounded; subterminal cells usually equally wide and usually branched, occasionally with lateral projections or nodulose. Pileocystidia near the pileus margin 1-celled, thick-walled, and relatively large pileocystidia often originating deep in subpellis and with embeded terminations; terminal cells (43–)48.2– 63.5 –78.8(–92) × (4.7–)4.6– 5.5 –6.4(–7) μm, cylindrical, subcylindrical to narrowly clavate, apically obtuse-rounded; content dense, heteromorphous, crystalline, without reaction in sulfovanillin (SV). Pileocystidia near the pileus centre often narrower and/or shorter, 1-celled, thick-walled; terminal cells (33–)37.3– 49.6 –62(–72) × (4–)3.8– 4.9 –6(–7) μm, cylindrical, subcylindrical to narrowly clavate, apically obtuse-rounded; content dense, heteromorphous, crystalline, without reaction in sulfovanillin (SV). Clamp connections absent from all tissues.

Habitat:—Solitary to scattered, growing in ectomycorrhizal association with species of Quercus , Rhododendron and Lyonia dominated temperate mixed forests.

Additional specimen examined:— INDIA. Uttarakhand, Rudraprayag district, Chopta-Baniyakund , N 30°29.376’ E 79°09.673’, elevation 2356 m, 25 th July 2016, A . Ghosh, AG 16-1206 ( CAL 1807 , paratype) .

Figures

FIGURE 2. Russula baniyakundensis (CAL 1806, holotype).a–c. Fresh and dissected basidiomata d. Transverse section through pileipellis showing elements e. Transverse section through lamellae showing hymenial cystidia near the lamellae sides and basidia (indicated in black arrow) f. Transverse section through lamellae showing hymenial cystidia near the lamellae sides g. Transverse section through lamellae showing hymenial cystidia near the lamellae edges h. SEM micrograph of basidiospores. Scale bars: a= 50 mm; d−g= 10 μm; h= 2 μm. Photos by: Aniket Ghosh.

FIGURE 3. Russula baniyakundensis (CAL 1806, holotype). a. Basidiospores b. Elements of the pileipellis near the pileus margin: hyphal terminations and pileocystidia c. Elements of the pileipellis near the pileus centre: hyphal terminations and pileocystidia d. Hymenial cystidia near the lamellae sides e. Hymenial cystidia near the lamellae edges f. Basidia. Scale bars: a= 2 µm; b–f= 10 µm. Drawings by: Aniket Ghosh.